Open-hearth furnace



' v1,627,425 May 3 1927 E. 'BossHARDT v OPEN HEARTH FURNACE Filed June 30. 1924' Patented May 3, 1927..

UNITED :STATES l 1,627,425l PATENT oFFlcE.

EDWIN' BOSSHARDT, 0F BERLIN-TEMPELHOF, GERMANY.

OPEN-mara nommen'.

application and :une so, 1924,- serial No.

, tering the melting chamber as these latter gases force away the producer gases in a lateral direction.

A further drawback consists in the fact that at the end of the furnace at which the burnt gases leave the melting chamber, the

roducer gases at that end, instead of flowlng to the opposite furnace head and entering the melting chamber together with the gases from the producer on that side, pass through the ports into the melting chamber directly and escape together with the burnt gases formed in the neighborhood of the urner into the discharge .channels where they burn uselessly, and produce heat which attacks there the refractory building material to a high degree.

These disadvantages are overcome by the improvements according tol the present invention by providin a preliminary chamber into which are con ucted the heating gases intended for the hearth and which are composed of the smouldering gases and of ythe producer gases, which lattermainly consist y' of carbon-monoxide. In this chamber an intimate mixing ofl these two kinds of gases occurs previous to their'being lead through the ports into the melting chamber.

Further the disadvantageous escape of the heating ases from the part adjacent to the `furnace liead into the outlet channels is prevented by providing for air to be blown across the slots at a point between the mixing chamber and the melting chamber at the head of the furnace through which the burntl gases' escape; the air acts as an obturation between the mixing chamber and the melting chamber and acts in the same manner as) i a valve or gate inserted at that place, cut-olf devices of this type, however, cannot be utilized on account of the very high 'temperatures.

The combination of the mixing chamber and the means for blowing air also causes a. cooling of the burner parts and of the outlet channels whereby the wear of theseparts is much reduced and the life of the furnace is greatly increased.

A constructional example of thefurnace rig. 1.

forming vaulted and 723,334, and in Germany october 25, 192s.

according to the present invention is dia-- grammatically illustrated on the accompanylng drawings, in which:

Fig. 1 is a vertical section through the improved open hearth furnace,

Fig. 2 is partly a section along line II-II of F1 ."1 and valve oxes and Fig. 3 is a section along line III-III of Referring now to the drawings, 1 designates the hearth or melting chamber and 2l the two head ends of the furnace. The gas producers 3 are arranged adjacent these heads and are provided with grates 4 which are charged by means of the loading hoppers 5.

8 denotes air chambers arranged beneath the hearth v1 and acting as regenerators to preheat the air in a known manner. Air flues 9 connect these chambers 8 to the furnace heads 2, the ends of these lues beino srranged in the upper art of the hea s 2 ownwardly directed ports 9', terminating above the art 2 of the .furnace heads which may be ca led the burner. The regenerators 8 are also connected by means of flues 10 to a chamber 12 provided with a butterfly reversing valve 11. A flue 13 connects the chamber 12 withv the chimney and a channel 14 connects said chamber with the atmosphere.

Flues 15 provided in the furnace heads 2 connect the upper end of each gas producer 3 with regulating or valve-boxes 16 provided with valves 17 adapted to -close the openings of the flues 18 leading from the regulatlng 4boxes 16 to the chambers 19. l

Pipe's 20 connect the regulating boxes 16 of one head of the :furnacel with the'boxes of the head on the other side of the furnace.

partly a section through the 21 denotes gas ports extending between the mixing chamber 19l and the melting chamber 1 and arranged at the level of the white heat zone of the generators and ending below the end of the air ports 9'; Slots 30 are further arranged ending in the ports 21 at a point between the chambers 19 and the melting chamber 1 and lead to the outside where they are connected to conduits 31 through which air can be blown, for instance, from a fan not shown on the accompan ing drawin Us T e process o? operating furnaces of this type is well known and is described in detail inthe specification of my .Letters Pat- 'the melting chamber 1 and the burnt gases escape through the ports 9 and flues 9 of 'the left hand furnace head into the left hand regenerator 8 and from therethrough the left hand flue 10 and flue 13 into the chimney. yThe two gas producers 3 Work simul-l taneously and the gas produced by the left hand producer'passes through the iues 15 and the pipes 20 into the right hand regulating boxes 16 while the gas produced by the right hand gas producer flows directly through the iues 15 into the right hand regulating boxes and through' the open valves 17 into the iiues 18 and into the mixing chamber 19 adjacent to the right hand gas-producer 3. In this chamber 19, which shall be called the mixing chamber, an intimate mixing of the gases from the gasproducers and of the smouldering gases derived directly from theright hand gas' producer takes place and the mixed gases flow then through the ports 21 in to the melting room. This mixture ensures'- a complete combustion of the heating gases from the two opposite gas'producers. The fact that the gas ports 21 are arranged at the level of the white heat Zone of the generators in combination with the intimate mixture of the heating gases renders it possible to obtain very high temperatures in the melting chamber. @wing to the high melting temperatures an absolutely pure and tough material is obtained and the time for melting a charge is considerably reduced.

In order to prevent gas from the left hand producer from entering the melting chamber through the ports 21 air is blown into thes ports through the slots 30. This air acts like a valveand presents the further advantage that it cools the left handl burner 2 and the adjacent channels and decreases thus the danger of their being prematurely destroyed by the heat.

The above described action is alternately reversed for the left hand and the right hand side` of the furnace whenl the positions of the reversing-valve 11 and the valves 17 are alternately reversed .in the knownl manner.

I claim:

1. A furnace of the open-hearth type comprising in combination, a meltin chamber, a gas producer at each end of t e melting chamber, a mixing chamber interposed between each gas producer and the furnace melting chamber and arranged at the level of the white-heat zone ofthe producers in open connection with the latter for access of the gases derived from that zone to said mixing chamber, means to interconnect the upper part of both producers, means on each furnace head to connect said interconnecting means to each mixing chamber and lead thereto the gases derived from the top of both producers for mixing, means to open said last mentioned connecting means on one furnace head and to close said means on the other furnace head and vice versa to render one of said mixing chambers operative and the other inoperative, and connecting means arranged at a level of the white heat zone between each mixing chamber and the melting chamber for supplying the gases from the operative mixing chamber to the melting chamber.

2. A furnace of the open-hearth type comprising in combination a melting chamber, a gas producer at each end of the melting chamber, a mixing chamber interposed between each producer and the melting chamber arranged at the level of the white heat zone of the-producer and in open connection with the latter to provide access thereto of the gases derived from that zone, means to interconnect the upper part of both producers, flues in each furnace head to con nectsaid interconnecting means to the respective mixing chambers to lead the gases from the tops of both generators to either of said mixing chambers and to cause these gases to mix therein with the other gases derived from said white heat zone, valves adapted to control said flues and to permit a flow through the flue in'one furnace head and prevent a flow through the flue in the other furnace head and thereby render one of said mixing chambers operative and the other inoperative, and gas ports arranged at the level of the white heat zone and connecting said mixing chambers to the-melting chamber for supplying the heating gases of the operative mixmg chamber to said meltv chamber, a mixing chamber interposed between each gas producer and the' melting chamberarranged at the level of the white heat zone of the producer and in open connection with the latter to provide for access of the gases derived from said zone to said mixing chamber, means to interconnect the upper part of both producers, fiues on each head of the furnace to connect said interconnecting means to thel respectivel mixing chamber for leading the gasesI derived from the top of both producers to either of said chambers and cause these gases to mix therein with the other gases derived from said mama and to permit a flow through the ilue in one furnace head and prevent a ilow through the flue in the other furnace head thereby rendering one of said mixing chambers operative and the other inoperative, slots arranged at the level of the white zone and ports .connecting said mixing chambers to the melting chamber, and means adapted to blow air into said slots for acting as a closure in order to prevent heating gases from secaping from the inoperative mixing cham- 4. An open-hearth furnace, comprising a gas producer, a melting chamber, a' gas port connecting-the chamber and producer -at the White heat zone ofthe latter and means to produce a cooling and obturating current of air across the ports.

.5. An open hearth furnace, comprising rent of air across sal two gas producers, a melting chamber, a gas passa e connecting the melting chamber and one .o the producers at the white heat zone of the latter, a mixing chamber forming psrt of said passage, land means to supply el gas from the other producer to said mixing chamber.

6. An o en-he'arth furnace, comprising a gas pr ucer, a melting chamber, a gas passage connecting the chamber and producer at the white heat zone of the latter, a mixing chamber formin part of said passage, means to supply fue gas to said chamber and means to supily an obturating curpassage between said mixin and melting chambers also operating to coo the port Walls.

In testimonylwhereof I ailix my signature.

EDWIN BOSSHARDT. 

